Question

Type 1. A farmer moves along the boundary of a square field of
side 10 m in 40 sec. What will be the magnitude of displacement
of the farmer at the end of 2 minutes 20 seconds and what is the
total distance covered by him? ​

Answer 1

Answer: Displacement= 10*root2 = 10*1.414= 14.14m

Distance= 140m

Explanation: In 40s the farmer covers a total of 40m (perimeter of square)

So in 2 min 20s ( 140s) the farmer completes three full rounds and one half round (140= 40+40+40+20)

thus the displacement from original position will be the diagonal of the square which is 10*root2 m

now, the distance,

he, in 40s covers 40m , I.e. one metre per second

hence in 140s  he will cover 140m